FDA probes blood cancer immunotherapy safety

The FDA is to probe safety concerns about cancer immunotherapies combinations in the light of signals from two trials involving Merck & Co’s Keytruda.

The FDA has notified healthcare providers of increased death risks associated with Keytruda (pembrolizumab) when used in combination with certain other drugs as an unapproved treatment for multiple myeloma.

The safety alert follows the FDA's decision in June to put on hold two multiple myeloma trials involving Keytruda because of the safety signal from the KEYNOTE-183 and KEYNOTE-185 trials.

These trials showed excess deaths in patients receiving it in combination with an immunomodulatory agent such as Celgene's Revlimid (lenalidomide) and Imnovid (pomalidomide).

[caption id="attachment_31285" align="alignnone" width="120"] Janet Woodcock[/caption]

There is no suggestion of any further safety issues in approved uses for Keytruda. But in a statement Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research, said the regulator is working with Merck & Co and manufacturers of other PD-1 and PD-L1 inhibitors to examine their use in blood cancer combination therapy trials.

The FDA will take “appropriate action” to ensure patients in these trials are protected, and doctors and clinicians understand the risks in this use.

Keytruda is currently approved by the FDA for treatment of: melanoma, lung cancer, head and neck cancer, classical Hodgkin lymphoma, urothelial carcinoma, and microsatellite instability-high (MSI-H) cancer.

Cancer immunotherapies are setting care standards in some diseases, but clinical trials are still throwing up some unwelcome surprises.

Around a year ago, Bristol-Myers Squibb’s Opdivo (nivolumab) flopped in a first-line lung cancer trial, and recently, AstraZeneca’s much-anticipated durvalumab and tremelimumab combination therapy failed to improve progression free survival in this indication.

Roche is also in a quandary after data from a late-stage trial failed to confirm the efficacy of its Tecentriq (atezolizumab) in bladder cancer, following approval based on immature data.